Clutch



y 942- c. K. RABER 2,289,884

CLUTCH Filed May 31, 1941- 2 Sheets-Sheet l 3 -o t 1 I I .5 FIG. 2

INVENTOR. I Clyde Afar/e Haber ATTORNEY.

Patented July 14, 1942 UNITED STATES PATENT OFFICE I 6 Claims.

'The object of my invention, broadly stated, is to provide a clutchmechanism which will automatically operate to unclutched status, and tobe held in said unclutched status, whenand during such time as thestrain to which the clutch mechanism is subjected, exceeds apredetermined limit therefor, thereby avoiding liability of injury orderangement in case of there being imposed thereon, a strain beyond saidpredetermined limit.

The above named general object, as well as other and more specific aimsof the invention having to do with structural improvements contributingto durability, efliciency, and economy of manufacture and maintenance,as will presently appear, are accomplished by, and the invention iscontained in the new construction, combination and arrangement of partsdescribed in the following specification, illustrated in theaccompanying drawings, and defined in the appended claims.

The several parts of the invention, as they appear in the differentviews in the drawings,

. structure's rotation.

are identified by suitable characters'of reference applied to them.

Figure 1 is a side elevational view of my improved clutch mechanism,portions of some of the parts being broken away, and other portionsbeing shown in central longitudinal cross section.

- Figure 2 is an end view, in the direction of arrow 2 in Figure 1,portions of the device being broken away.

Figure 3 is an end view, on the broken line 3-4, in the direction ofarrow 3 in Figure l, portions of thethrust structure and portions of theretainer ring being broken away.

Figure 4 is a vertical-cross section view, on the broken line 4-4, inthe direction of arrow 4 in Figure 1.

Figure 5 is an enlarged cross section view,.on the line 5-5 in thedirection of arrow 5 in Figure 2. v

Figure 6 is an enlarged detailed cross section view on the line 6-6, inthe direction of arrow 6, in Figure 2. I

Figure 7 is a side view of the helical spring removed, as seen in thedirection of arrow i in Figure 4.

My invention is especially adaptable to, and it is shown herein asexemplified in a rotating shaft clutch of the type in which a helicalspring carried by one main structure, fits within or upon the other mainstructure and through the ex panding of the spring, or the contractingof the spring, as the construction may be, the two structures becomelocked in driving and driven rela- Inthe present embodiment of myinvention, and which is designed for the heavier duty which is imposedupon machines such as power presses or the like, the several parts ofthe invention are of the construction, coordination and arrangement asfollows: x

A driven structure consists of a drum l5 of open cylindrical formationand which embodies h'ub portion l1 which is adapted tb receive and tohave secured thereto, as by a key l8, a power shaft P. Wall l6 of thesaid drum embodies an axial boss l9 machined to formation so that itconstitutes annular seat 20, vertical face 2|, and marginal annular'fiange 22. I

The open or rim portion of said drum embodies shallow external flange23. At each of equably spaced locations, six in the present instance,upon the interior of the drum, is secured a pillow block 21 providedwith cross pin 28 upon which is fulcrumed a lever 29 whose power arm 30is provided a with eye 3|. The weight arm of said lever is F bifurcated,the side members 32 thereof having their free ends of rounded formation,as indicated .in Figure 5.

Extending longitudinally through said boss i9 and the wall of said drumand in alignment with the eye 3| of the said lever, is a hole 33, andadjacent thereto is a larger hole 34, the latter being threaded at itsinner end.

Disposed upon said drum, in contracted status, is a helical spring 38whose coils, preferably square in cross section, have their lateralexternal faces at their endportions machined so that th'ey are inparallelism. In one end portion and which may be designated as theoutboard coil 39, are spaced recesses 40; and in the other end portion,designated as the inboard coil 4 l, are spaced recesses 42. The rimflange 23 of the said drum constitutes an annular abutment against whichthe outboard coil 39 of'said spring is in contact while the spring is inthe contracted status.

The driving structure 46, circular in formation, is adapted to receivepower transmission of any usual description, such as belting (not shown)to run in peripheral grooves 41 provided therefor. It embodies verticalwall 48 and hub 49, the latter being. journaled as by antifrictionbearings 50 on the hub ll of the said drum. Bore 53 of said drivingstructure is of diameter predeterminately greater than the externaldiameter of said drum. Provided in said driving st ucture 5 is acounterbore 54 which is of external side face of said follower.

length about one half of the length of the aforesaid bore 53.

In each of equably spaced locations on the outboard face of the wall 48of said driving structure and in proximity with the hub portion thereof,is a pocket 56 in which is retained a protractive coil spring 51. i

In counterbore 59 of each of equably spaced longitudinal holes 80 whichare adjacent to the said bore 53 and which extend throgh the wall ofsaid driving structure 48, is a protractive spring ii. The inner endportion of a bolt 62 whose integral annular collar 63 bears against saidspring 8| is received in said hole 80, and itsouter end is received freein the bore of a countersunk threaded ring 84 that is flush with theface of said wall, and which constitutes an abutment against which thecollar 03 of said bolt is yieldingly held by the said spring, asillustrated in detail in Figure 5.

A member which is adapted to be driven, in

I the manner presently to be described, consists of an annulus 88, andwhich I designate as a follower. It is of external diameter to bereceived in the counterbore 54 of the said driving structure,

and its wall is of internal diameter to be received on the annular seat20 of boss I9 of the said drum. The bore 61 of said follower is ofdiameter the same as that of the bore 53 of the said driving structure.At each of equably spaced locations, six in the present instance, isfixedly secured a stud 88 which embodies a tapered head 69 and whichprotrudes from theextemal side face of said follower. In each of equablyspaced locations, on the inner face of the wall of said follower andadjacent to the bore 81 thereof, is a stud I0. The spacing of thesestuds is the same as the spacing of the recesses 42 of the inboard coilof said helical spring 38.

Figure 6 is now referred to. Provided in the external side face of thecircumferential portion of said follower 66 are similarly equably spacedrecesses II. Each is of predetermined length and depth, and said depthis of decreased dimension at the outboard portion I2 thereof. Extendingfrom said recess at a right angle thereto and radially of said followeris a bore I3 in which is contained a coil spring I4. Disposed upon saidcoiled spring is a movable device such as a roller I5 of diameterequivalent to the depth of, and of length to freely reside in saidrecess, In a threaded hole II that extends from the circumferentialface' of said annulus into the outboard portion I2 of said recess, is adepresser screw 18 the inner end of which is in registration with theentrance to the portion I2 of said recess. The features just describedwill be presently referred to.

Lug ring 80 which is disposed on the annular flange 22 of the boss I9 ofthe driven structure is provided with holes 8i and 82 which are spacedto register with the holes 33 and 34 respectively of the said drum. Saidlug ring is also provided with cone shaped openings 83 which are spacedto receive, and in which reside the tapered heads 89 of the studs 68when the said lug ring is placed in its position of face to facerelation with the It will be observed now, (referring to Figure 6) thatthe plane of the inner vertical face of the said lug ring is coincidentwith the plane of the circumferential faces of the said rollers I5.

Passed through each of the said holes 82 of said lug ring, and screwedto secure position in the threaded hole 34 of the said drum, is a stemlatter to positive and firm status in its seated position, as shown inthe drawings, may be varied. By a device such as a set screw 89 or thelike, the said head nut may be made fast at the position to which itwill have been adjusted.

A pull rod 9i retained free in each of the holes 8| of the said lug ringis passed through the hole 33 of said drum and through the eye 3| ofsaid lever 29, and has its inner end provided with a binding nut 92.

A protective shield for the said lug ring and the related parts thereofmay consist of a light metal cap 94 made fast to the lug ring as by capscrews 95.

I A thrust structure consists of an out-pressure ring IOI, so calledbecause of its being adapted to be moved in the direction of arrow 0, inFigures 1 and 5 or de-thrustwise, having equably spaced forwardlyprojecting struts having an axial boss I03 with threaded bore. This ringis disposed with its studs passed through apertures 45 therefor providedin wall 48 of the said first section of the driving structure.Anin-pressure member, so called because of its being adapted to be movedin the direction of arrow I, in Figures 1 and 5 or thrustwise, consistsof a ring shaped plate I04 provided with spaced holes in which arereceived the bosses of the said struts I02. With the cap screws I05screwed home on the counterbored seats therefor in said ring plate I04,the completed thrust structure appears in cross section as in Figure 5,the springs 51 urging the said ring plate I04 outwardly to the limitdictated by the length of said struts and by the ring I 0| coming toengagement with the inner face of said wall 48. The internal diameterI06 of said ring plate is such as to clear the hub 49 of the drivingstructure; and the raised annular face I 0'I accommodates the bearingsof an actuating device of any conventional kind.

Preparatory to combining the driving structure 48 and the thruststructure IOI I02I04, with the follower 66, the binding nut 92 on thepull rod 9| is screwed against the power arm 30 of the lever 29, thenose portion of the weight arm being brought to a plane that is distantfrom the vertical face of said drum, a measure of the thickness of thering I 0| plus the depth of the recesses 40 of the outboard coil of thehelical spring assuming the said ring to be at the outwardly pressedposition.

The slight spacing (see Figure 5) between the external face of thehelical spring, and the common bore 536'I of the driving structure andfollower, exaggerated for clarity of illustration, indicates theclearance which actually exists in practice and which amounts to severalthousandths of an inch.

A metal ring H0 which is mounted, and is held non-rotatively, as by apin III, on the hub II of the said driven structure, lies immediatelyagainst the vertical face of the hub 49 of the driving structure, and itconstitutes a lateral bearing for said hub, and also a closure of thespace within which the anti-friction bearing 50 is retained. A stay ringIIZ which is screwed on the hub I I to tightened relation with said ring"-0 stays the latter, and, in turn, it is fixedly secured by a lockscrew H3.

I02, each as ess consist of a conventional lever ||4 fulcrumed on Abracket or brackets H5 supported by an adjacent fixed objecitsuch asframe F of machine having powershaft P, the ends 6 of the forked weightarm of said lever having anti-friction bearings 8 to engage the annularrace |||I of the thrust member )4, and the 'power arm Ill of saidlever-being connected to operating devices (not shown);

The invention in readiness for use appears as in Figure 1, the thruststructure being in the outwardly urged position, in the direction ofarrow 0, by the springs 51 and resisting the lesser urge by the actuatorlever H4. The bolts 62 are in the outwardly urged position, by thesprings 8|. Helical spring 38 rests with its outboard coil ll abuttingagainst flange 23 of the drum |5,-andits inboard coil 4| in engagementwith the anchor studs Ill and against the inner face of the follower 66.

Lug ring 80 by the urge of the springs 81' is heldwith its inner faceagainst the outer face of the wall of said follower 66.

The direction, assumed, inwhich the driving structure is rotating, isanti-clockwise, as indi cated by the arrow AC in Figure 1.

Upon actuating the lever 4 (by means not shown) the thrust structure'ismoved in the direction of arrow I. In this move, the pressure exerted bythe ring I04 against the bolts 62 cause the latter to move inwardlywhence they come into engagement with the recesses 40 of the outboardcoil 39 of the helical spring. The inboard coil 4| of said spring beinglll'flllChOled connection (at studs 10) with the follower 66, the coilsof the said spring are'caused to expand whence they come into frictionalmetal to metal engagement with'the bore 53 of the driving structure, andthe bore 61 of the follower. The power of the driving structure 46 istransmitted through the coils of the helical spring and through the Ifollower 66, the tapered studs 69, lug ring 80 and stems 86 to the druml5 which now is being driven. I

The driving action proceeds normally until there'occurs an overload.Upon the occurrence of a load'in excess of the degree of capacity forwhich the tension of the springs 81 and the taper, 69 of the studs 68will have been provided, the

studs 68 and the springs 81, and the latter, yielding to the stress ofsaid reverse urge of the lug ring, permits the latter to move fromitsnormal of the said drum, and l-the said driven structure will havecome torest.

m the meantime (see Figure 6) therollers 1s will, by the urge'of thefprings I4, have been projected from their normal positions into theoutboard portions '12 of the recesses .II, and in which said projectedpositions theyare, bythe urge of the springs 14 retained, thereby thelug ring being held in position spaced from the follower ii.

After the cause of the overload is removed and the normal action of themechanism is to be resumed, the screws 18 are turned inwardly, therebyforcing the rollers 15 to their normal positions in their recesses.Then, by the urge of the springs 81, the lug ring is pressed to itsnormal position in direct and firm union with the follower 66. Theoperator now drives the screws 18 to their normal positions as shown inFigure 6, and the mechanism is again in readiness for use.

position longitudinally. Insuch yield, the lug ring rides on the taperedlugs and in the direction of the arrowI (Figures 1 and 5). In this moveof the said lug ring, the pull rods 9|, actuating the levers 29 causethe weight arms 32 of from the outboard coil 39 of said helical spring.I The said helical spring having become contracted, it will have becomedisengaged from the bore 53 ofthe driving structure, and the bore 61 ofthe follower and its outboard coil 39 will have resumed its positionengaged with the rim flange 23 In predetermining the resistance intendedto be offered by the lug ring to the forces (inci-'- dent to overload)tending to dislodge it, from its normal position, there is taken intoaccount the degree ofv tension of the springs 81, [and the degree oftaper of the studs 69. It isconsidment of the lug ring when the loadbeyond the limit prescribed for the machine may occur. The heavier thepredetermined load limit, the lesser is the incline of the taper of thesaid studs.

It will be understood that the invention described, is subject to suchchanges, modifications and departures from what is specifically,il1ustratedand s may occur to those skilled in the artto whi,h theinvention appertains. without departing from the principle of theinvention and as defined in the appended claims.

What I claim as my invention, is:

l. A .clutch mechanism comprising an open cylindrical driven -structureembodying. a hub adapted to be fixed to a shaft and the wall thereofembodying a circular axial boss provided with annular flange, a drivingstructure embodying a wall, a bore, and a counterbore, a driven memberannular in formation and reposed in the said counte'rbore and having-abore of diameter the sameasthe bore of the said driving structure, thecommon diameter of the said bores being of dimension predeterminatelygreater than the external diameter of the said driven structure, spaced.externaltapered lateral studs on said annular driven member, spacedinternal longi-.- tudinal anchor studs on the said 'annu1ar driven.member and adjacent to the bore thereof, the

said driving structure so constituted as above described being mountedfor rotative movement and being retained in coordinated relation with 3the said driven structure, a helical spring comprising inboard andoutboard coils reposed on the driven structure the externalface of theend of the outboard coil, and the external face of the end of theinboard coil thereof being in parallel alignment and each f said iacesbeing .provided with spaced recesses, the recesses of the inboard coilbeing adapted to be engaged by said anchor studs, a lug ring retained onthe annular flange of he bOSs of said driven structure and held aga trotative movement thereon, means to hold the lug ring yieldably againstlongitudinal movement, the said lug ring being provided with taperedrecesses in which are received the aforesaidtapered studs of the saidannular driven member, bolts loose in longitudinal apertures therefor inthe wall of the said driving structure, spaced with relation to thespacing of the recesses of the outboard coil of said helical spring, andwhich said bolts are adapted to be moved inwardly and to engagement withsaid recesses, means to urge the said bolts outwardly, a longitudinallymovable thrust structure carried by the driving structure and which isadapted to be moved to and held in pressing engagement with said bolts,whereby by the engagement of the bolts in the recesses of the outboardcoil of said helical spring, and by engagement of the recesses of theinboard coil of said spring at the said anchor studs, the said spring iscaused to expand to driving contact with the common bore of the drivingstructure and the said annular driven member when the spring isoperated, and shifter devices carried upon the interior of the drivenstructure which are operable when the lug ring is caused to be movedfrom its normal position, to shift the thrust structure whereby theaforesaid bolts are rendered ineffective to retain engagement with saidhelical spring, the latter thereby being permittedvto contract, thepower transmitting relation between said driving structure and saidannular driven member being thereby discontinued.

2. A clutch mechanism comprising an open cylindrical driven structureembodying a hub and a circular axial boss, a driving structure embodyinga wall, a bore and a counterbore, an annular driven member reposed inthe counterbore and having a bore of diameter the same as the bore ofthe said driving structure, the common diameter of the said bores beingof dimension predeterminately greater than the external diameter of saiddriven structure, spaced external tapered studs on said annular drivenmember, spaced internal anchor studs on the annular driven member andadjacent to the bore thereof, the said driving structure and saidannular driven member being mounted for rotative movement and beingretained in coordinated relation with the said driven structure, ahelical spring comprising inboard and outboard coils reposed on thedriven structure, the external face ofithe end of the outboard coil, andthe external face of the end of the inboard coil being in parallelalignment, the external face of the inboard coil being adapted forengagement with the said anohor studs, spaced stems projectinglongitudinally from said driven structure, a lug ring retained on saidstems, the said lug ring having tapered recesses in which are receivedthe aforesaid tapered studs, a protractile coil spring on each of saidstems adapted to bear against said lug ring, a nut threaded on each stemto hold the spring at adjusted tension, bolts loose in longitudinalapertures therefor in the wall of the driving structure and in alignmentwith and adapted to be engaged by the outboard coil of said helicalspring, means to urge said bolts outwardly, a longitudinally movablethrust structure adapted to be moved to and held in pressing engagementwith said bolts, shifter devices carried upon the interior of saiddriven structure operable to shift the thrust structure outwardly, andpower transmitting members interconnecting the lug ring and said shifterdevices to actuate the latter when the lug ring is moved longitudinally.

3. A clutch mechanism of the kind described,

comprising a drum embodying a hub and a circularaxialboss, a drivingstructure embodying 'being of diameter predeterminately greater than thediameter of said drum, and the said follower being retained on the bossof said drum, spaced external tapered studs on the external face of saidfollower, spaced internal anchor studs on the interior of said followerand adjacent its bore, a helical spring comprising inboard and outboardcoils reposed upon said drum, the external faces of the outboard andinboard ends of said spring being parallel, and the external face of theinboard coil being adapted for en gagement with said anchor studs,spaced stems projecting from said boss, 2, lug ring retained on saidstems and having recesses in which the said tapered lugs are received, aprotractile coil spring on each of said stems adapted to bear againstsaid lug ring, a nut on each stem to hold the said coil spring atadjusted tension, bolts loose in the wall of said driving structure andin alignment with and adapted to be engaged by the outboard coil of saidhelical spring, springs to urge said bolts outwardly, a longitudinallymovable thrust structure carried by said driving structure and adaptedto be moved to pressing engagement with said bolts, shifter devicescarried by the drum operable to shift the thrust structure outwardly,power transmitting members interconnecting the lug ring and said shifterto actuate the latter when the lug ring is moved longitudinally, andstay devices that are automatically operable to stay the lug ring afterit will have been so moved.

4. A clutch mechanism comprising a driving member, a follower, a drivenmember, a power transmitting device carried by the driven member andwhich is operable to engagement with the driving member and thefollower, bolts carried by the driving member and urged to positionnormally disengaged from, but which are adapted to be moved toengagement with the said power transmitting device to actuate thelatter, a thrust structure movable thrustwise to move said bolts to andto hold them in engagement with said power transmitting device, anddethrustwise to permit said bolts to become disengaged from said powertransmitting device, shifters carried by the driven member operable tomove the thrust structure dethrustwise, a lug member carried by thedriven member and which is yieldably coupled to said follower, and powertransmitting parts interconnecting the lug member and the shifterswhereby upon the lug member yielding its position the thrust structureis automatically moved dethrustwise.

5. A clutch mechanism, comprising a driving member, a follower, a drivenmember of diameter to provide an annular cavity between it and thedriving member and follower, a helical spring carried by the drivenmember and which is operable to, engagement with the driving member andfollower, bolts carried by the driving member and urged to positionsnormally disengaged from but which are adapted to be moved to engagementwith the said spring to actuate the latter, a, thrust structure operablethrustwise to move said bolts and to hold them in engagement with saidspring, and dethrustwise to permit them to be disengaged from saidspring,

dethrustwise, to stay the lug member against return to its normalposition. i

6, A clutch mechanism, comprising a driving member, a followerconcentric therewith and being provided with lateral spaced externaltapered studs, a driven member of diameter to provide an annular cavitybetween it and the driving member and follower, a helical spring carriedby the driven member and which is operable to engagement with thedriving member and follower,

bolts carried by the driving member and urged to position normallydisengaged from but which are adapted to be moved to engagement with thesaid spring to actuate the latter, a thrust structure carried by thedriving member and operable thrustwise to move said bolts to and to holdthem in engagement with said spring, and dethrustwise to permit them tobecome disengaged from said spring, shifters carried by the drivenmember operable to move the thrust structure dethrustwise, an annularlug member carried by the driven member and having spaced cone shapedrecesses in which are received the afore said tapered studs of saidfollower, means ,car-

ried by the driven member to yieldably retain the lug member againstsaid follower, power transmitting parts interconnecting the lug memberand the shifters, and stay devices carried by the follower that areautomatically operable to stay the lug member in position spaced fromthe follower, when said lug member will have become displaced;

CLYDE KYRLE RABER.

